วันพุธที่ 15 เมษายน พ.ศ. 2569

Papilledema

Papilledema

1. Definition

  • Papilledema = optic disc swelling จาก ↑ intracranial pressure (ICP) เท่านั้น
  • ต่างจาก:
    • optic disc edema (สาเหตุอื่น เช่น ischemia, inflammation)

2. Etiology ของ ↑ICP (high-yield)

กลุ่มหลัก

  • Brain mass (tumor, hemorrhage)
  • Cerebral edema (trauma, hypoxia)
  • CSF flow obstruction → hydrocephalus
  • Venous outflow obstruction (CVT)
  • Idiopathic Intracranial Hypertension
  • Rare: CSF overproduction

3. Pathophysiology

  • ↑ICP → pressure transmitted via subarachnoid space
  • → block axoplasmic flow
  • → optic disc swelling
  • → late: axonal damage → vision loss

4. Clinical Features

Key concept:

👉 Vision มักปกติใน early stage (สำคัญมาก)

Symptoms

  • Transient visual obscurations (seconds–minutes)
  • Headache (↑ with Valsalva)
  • Nausea/vomiting
  • Diplopia (CN VI palsy)
  • Pulsatile tinnitus

Vision loss

  • Late finding
  • เริ่มจาก:
    • enlarged blind spot
    • peripheral constriction

5. Fundoscopic Findings (progression)

Early

  • blurred disc margin (inferior/superior → nasal → temporal)
  • hyperemia
  • venous congestion
  • absent venous pulsation

Established

  • disc elevation
  • flame hemorrhage
  • cotton wool spots
  • Paton lines
  • loss of cup

Chronic → Atrophic

  • pale disc
  • gliosis
  • optic atrophy → permanent vision loss

6. Key Differentiation (สำคัญมากใน practice)

Feature

Papilledema

Optic neuritis

NAION

Vision early

Normal

↓

↓

Pain

❌

✅

❌

Laterality

Bilateral

Uni

Uni

RAPD

Late

Early

Early

VF

blind spot

central

altitudinal


7. Papilledema Mimics (ต้องแยก)

7.1 Optic disc drusen

  • pseudopapilledema
  • no hemorrhage / congestion

7.2 Hypertensive optic neuropathy

  • BP สูงมาก
  • retinal ischemia signs

7.3 Non-Arteritic Anterior Ischemic Optic Neuropathy

  • vision loss ตั้งแต่แรก
  • disc pallor

7.4 Optic neuritis

  • pain + vision loss

7.5 Neuroretinitis

  • macular star

8. Diagnostic Approach (ER priority)

Step 1: Confirm papilledema

  • Bilateral disc edema
  • Vision relatively preserved

Step 2: Immediate evaluation

  • BP measurement (exclude malignant HTN)
  • Neuro exam

Step 3: Imaging (urgent)

  • MRI brain + contrast
  • ± MRV (suspect venous sinus thrombosis)

Step 4: Lumbar puncture (after imaging)

  • Measure opening pressure
  • CSF analysis

👉 cutoff:

  • 25 cmH₂O (adult) = abnormal

9. Additional Tools

  • Ocular ultrasound → ↑ optic nerve sheath diameter
  • Visual field → blind spot enlargement
  • OCT → monitor edema / differentiate drusen

10. Management

Principle:

👉 Treat underlying cause + ลด ICP

Options

  • Mass → surgery
  • Hydrocephalus → CSF diversion
  • IIH:
    • weight loss
    • acetazolamide
  • Refractory:
    • CSF shunt
    • venous sinus stent
    • optic nerve sheath fenestration

11. Prognosis

  • Early: reversible
  • Late (atrophic stage):
    • permanent vision loss

12. Key Clinical Pearls

  • Papilledema = neurologic emergency until proven otherwise
  • Vision preserved early = clue สำคัญ
  • Always imaging ก่อน LP
  • Bilateral disc edema ≠ papilledema เสมอ (ต้องแยก mimic)
  • Blind spot enlargement = early VF defect
  • RAPD → คิด diagnosis อื่นก่อน

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